1. Field of the Invention
The present invention relates to mobile radio systems, and more particularly to cellular mobile radio systems.
Due to the mobility of mobile radio stations, the assignment to a radio cell in cellular radio networks, particularly mobile communication networks, is not fixed but, rather, must be matched to the respective conditions depending upon location and broadcast conditions, i.e. corresponding reassignments are necessary. When these reassignments are carried out by the mobile radio stations, then the radio frequencies of the paging channels of the neighboring radio cells coming into consideration must be known for comparative level measurements in order to be able to determine the neighboring radio cell paging channel to be classified highest in terms of quality and, therefore, to also be able to determine that neighboring radio cell to which, if necessary, the reassignment is to occur. Due to fluctuations of field strength, such measurements must be able to repeatedly executed and at short time intervals.
2. Description of the Prior Art
A proposed method which employs a network-wide information channel for the above purpose has the disadvantage that the mobile radio station must already be situated in or in the direct proximity of the corresponding radio cell so that the transmitted information can be received, since pure level measurements do not suffice.
A further disadvantage is that a constant synchronization with the network-wide information cycle is required for reassignments and the full information cycle must always be received since the network-wide information cycle cannot generally take the respective local neighborhood conditions into consideration. This operating mode is not optimal since, for example, it is not possible to be able to undertake the load distribution to the individual paging channels of one radio cell and, in particular, in such a manner that mobile radio stations coming from different neighboring radio cells employ correspondingly-assigned paging channels.